WebServlet.Sqlite OkHttp实现账户管理系统的设计

注意：

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**out.println();向用户交互信息

**类型用户的选择type

**增加 删除 修改的Scanner()语句不能加到servelet界面中

**数据库要关闭   防止数据库出现已经锁死的现象   流也要关闭

**OKhttp的使用

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1.建立数据库

[代码]java代码：

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1	create user(name text,pwd text);

 

2.插入数据(省略)

3.serelet 服务器端

 

login.java

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[代码]java代码：

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package demo01;   import java.io.IOException; import java.io.PrintWriter; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.Statement; import java.util.Scanner;   import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;   /**  * Servlet implementation class   Login  */ @WebServlet("/login.do") public class Login extends HttpServlet {     private static final long serialVersionUID = 1L;                   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {         response.setContentType("text/html;charset=UTF-8");         PrintWriter   out=response.getWriter();         String   name=request.getParameter("name");         //String   pwd=request.getParameter("pwd");         if(name!=null){             name=new String(request.getParameter("name").getBytes("ISO-8859-1"),"UTF-8");         }         out.println("欢迎您 !"+name);         System.out.println(request.getRemoteAddr()+"-"+name);     }       /**      * @see   HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)      */     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {         response.setContentType("text/html;charset=UTF-8");         PrintWriter   out=response.getWriter();         request.setCharacterEncoding("UTF-8");         String    name=request.getParameter("name");         String   pwd=request.getParameter("pwd");         String   type=request.getParameter("type");                   if(type.equals("login")){         try {             String   sql="select * from user where name=? and pwd=?";             Class.forName("org.sqlite.JDBC");             Connection   conn=DriverManager.getConnection("jdbc:sqlite:/c:/sqlite/db/my.db");             PreparedStatement   stmt=conn.prepareStatement(sql);             stmt.setString(1,name);             stmt.setString(2,pwd);             ResultSet   rs=stmt.executeQuery();             if(rs.next()){                 out.println("登录成功!欢迎"+name);             }else{                                   out.println("用户名或密码错误!");             }             rs.close();             stmt.close();             conn.close();             out.close();         }   catch (Exception   e) {             e.printStackTrace();         }     }else if(type.equals("A")){         try {             String   sql="select * from user";             Class.forName("org.sqlite.JDBC");             Connection   conn=DriverManager.getConnection("jdbc:sqlite:/c:/sqlite/db/my.db");             PreparedStatement   stmt=conn.prepareStatement(sql);             ResultSet   rs=stmt.executeQuery();             while(rs.next()){                 out.println("姓名:"+rs.getString(1)+"----"+"密码:"+rs.getString(2));             }             stmt.close();             rs.close();             conn.close();             out.close();         }   catch (Exception   e) {             e.printStackTrace();         }               }else if(type.equals("B")){                     String   sql="insert into user values('"+name+"'"+","+"'"+pwd+"'"+")";                   try {             Class.forName("org.sqlite.JDBC");             Connection   conn=DriverManager.getConnection("jdbc:sqlite:/c:/sqlite/db/my.db");             Statement   stmt=conn.createStatement();             int rs=stmt.executeUpdate(sql);             if(rs>0){                 out.println("添加成功!");             }else{                 out.println("添加失败！");             }             stmt.close();             conn.close();             out.close();         }   catch (Exception   e) {             e.printStackTrace();         }               }else if(type.equals("C")){          String   sql="update user set pwd="+"'"+pwd+"'"+"where   name="+"'"+name+"'";           try {             Class.forName("org.sqlite.JDBC");             Connection   conn=DriverManager.getConnection("jdbc:sqlite:/c:/sqlite/db/my.db");             Statement   stmt=conn.createStatement();             int rs=stmt.executeUpdate(sql);             if(rs>0){                   out.println("修改成功!");             }else{                   out.println("修改失败 ！");             }             stmt.close();             conn.close();         }   catch (Exception   e) {             e.printStackTrace();         }     }else if(type.equals("D")){         String   sql="delete from User where name="+"'"+name+"'";         try {             Class.forName("org.sqlite.JDBC");             Connection   conn=DriverManager.getConnection("jdbc:sqlite:/c:/sqlite/db/my.db");             Statement   stmt=conn.createStatement();             int rs=stmt.executeUpdate(sql);                           if(rs>0){                  out.println("删除成功!");             }else{                  out.println("删除失败!");             }             stmt.close();             conn.close();         }   catch (Exception   e) {             e.printStackTrace();         }                         }                                         }   }

 

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4.实现测试类

Oklogin.java

[代码]java代码：

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package demo01;     import java.io.IOException; import java.util.Scanner;   import okhttp3.FormBody; import okhttp3.OkHttpClient; import okhttp3.Request; import okhttp3.RequestBody; import okhttp3.Response;   public class Oklogin   {       public static void main(String[]   args) {         boolean flag=false;         Scanner   sc=new Scanner(System.in);         System.out.println("欢迎进入学生管理系统的登录页面！");         System.out.println("请输入用户名:");         String   name=sc.nextLine();         System.out.println("请输入密码:");         String   pwd=sc.nextLine();         String   type="login";         OkHttpClient   client=new OkHttpClient();         RequestBody   body=new FormBody.Builder().add("name",name).add("pwd",pwd).add("type",type).build();         Request   request=new Request.Builder().url("http://localhost:8080/week/login.do").post(body).build();         try {             Response   response=client.newCall(request).execute();             if(response.isSuccessful()){                 System.out.println(response.body().string());                 flag=true;             }         }   catch (Exception   e) {             e.printStackTrace();         }                   if(flag){             load();         }               }       private static void load()   {          while(true){                 System.out.println("欢迎来到学生账号信息管理系统:");                 System.out.println("--------------------------");                 System.out.println("1:增加用户信息");                 System.out.println("2:删除用户信息");                 System.out.println("3:修改用户信息");                 System.out.println("4:查看用户信息");                 System.out.println("5:退出系统!");                 System.out.println("----------------------------");                 System.out.println("请选择:");                 Scanner   sc=new Scanner(System.in);                 int choose=0;                 while(true){                     try {                         choose   = sc.nextInt();                         break;                     }   catch (Exception   e) {                         sc.next();//清除上次输入的信息                         System.out.println("请输入合法信息:");                                               }                 }                 switch (choose) {                     case 1:                         addUser();                         break;                     case 2:                         deleteUser();                         break;                     case 3:                         modifyUser();                         break;                     case 4:                         findAllUser();                         break;                     case 5:                         System.out.println("退出成功!");                         return;                 }                  System.out.println("按任意键回到首页:");                  String   name=sc.next();                 }//while               }       private static void deleteUser()   {         Scanner   sc=new Scanner(System.in);         System.out.println("请输入您删除的用户名:");         String   name=sc.nextLine();         String   type="D";         OkHttpClient   client=new OkHttpClient();         RequestBody   body=new FormBody.Builder().add("name",name).add("type",type).build();         Request   request=new Request.Builder().url("http://localhost:8080/week/login.do").post(body).build();         try {             Response   response=client.newCall(request).execute();             if(response.isSuccessful()){                 System.out.println(response.body().string());             }         }   catch (Exception   e) {             e.printStackTrace();         }               }       private static void modifyUser()   {         Scanner   sc=new Scanner(System.in);         System.out.println("请输入您修改的用户名:");         String   name=sc.nextLine();         System.out.println("请输入您修改的密码:");         String   pwd=sc.nextLine();         String   type="C";         OkHttpClient   client=new OkHttpClient();         RequestBody   body=new FormBody.Builder().add("name",name).add("pwd",pwd).add("type",type).build();         Request   request=new Request.Builder().url("http://localhost:8080/week/login.do").post(body).build();         try {             Response   response=client.newCall(request).execute();             if(response.isSuccessful()){                 System.out.println(response.body().string());             }         }   catch (Exception   e) {             e.printStackTrace();         }                   }       private static void addUser()   {         Scanner   sc=new Scanner(System.in);         System.out.println("请输入添加的用户名:");         String   name=sc.nextLine();         System.out.println("请输入添加的密码:");         String   pwd=sc.nextLine();         String   type="B";         OkHttpClient   client=new OkHttpClient();         RequestBody   body=new FormBody.Builder().add("name",name).add("pwd",pwd).add("type",type).build();         Request   request=new Request.Builder().url("http://localhost:8080/week/login.do").post(body).build();         try {             Response   response=client.newCall(request).execute();             if(response.isSuccessful()){                 System.out.println(response.body().string());             }         }   catch (Exception   e) {             e.printStackTrace();         }         }     private static void findAllUser()   {         String   type="A";         OkHttpClient   client=new OkHttpClient();         RequestBody   body=new FormBody.Builder().add("type",type).build();         Request   request=new Request.Builder().url("http://localhost:8080/week/login.do").post(body).build();         try {             Response   response=client.newCall(request).execute();             if(response.isSuccessful()){                 System.out.println(response.body().string());             }         }   catch (Exception   e) {             e.printStackTrace();         }         } }

 

 

原文链接：http://www.apkbus.com/blog-813041-61027.html